Rechargeable batteries, based on nickel-zinc cells, have drawn attention from time to time since at least the 1930s. These batteries offer potential advantages over other rechargeable, alkaline systems in terms of energy output and/or cost. For example, a nickel-zinc battery potentially equals the performance of a silver-zinc battery, but at an obviously lower, material cost.
The nickel-zinc battery has been plagued with abbreviated life and installation cost. These problems have arisen largely due to difficulties in production, and behavior in use, of the electrodes, particularly the zinc electrode. During normal cycling, the zinc electrode tends to replate in a non-uniform manner during recharging. Also, dendrites, growing out from the zinc electrode, tend to cause short circuiting during discharge of the battery.
Recently, attention has been directed to the potential that the nickel-zinc battery has, as a replacement for the lead-acid battery, in automotive vehicles. This replacement would be particularly desirable since the nickel-zinc battery could provide a substantially greater, driving range before recharging.
Currently, however, except for special applications, there is no commercial production of a nickel-zinc battery. A major factor lies in the problems that arise in production and use of the electrodes.
There is, then, an apparent need for improvements in the manufacture of electrodes for a nickel-zinc battery. This is particularly true of the zinc electrode which appears to be the primary source of problems.
It is a basic purpose of this invention to meet the need for improved, electrode production.
Another purpose is to provide a stronger, more homogeneous material for production of zinc and nickel electrodes.
A further purpose is to provide a rapid, efficient and cost-effective process for extrusion of electrode material.
A still further purpose is to provide a novel, extruder assembly for processing electrode material.